With the crisis associated with diminishing amounts of fossil fuel and the rapidly increasing prices for this fuel, there has been a great deal of interest in improving fuel economy, that is, the number of miles obtained in a given vehicle per liter of fuel.
Pentaerythritol mono-oleate is an additive which has been widely used, especially in the industrial oil area, and at low concentrations, that is less than about one-half of one percent, in the industrial oils. It is known to be an oiliness agent; however, since piston and ring lubrication is predominantly hydrodynamic, gains in fuel economy through the use of additives in the lubricating oil which reduce the coefficient of friction in mixed lubrication will probably be small and difficult to assess.